In May 2008, BDS was contacted by a member of the SWHRL Neighborhood Association requesting a presentation on the Southwest Hills geology, landslides and hazards. In the past, BDS has presented similar topics at our Lunch & Learn series outreach offered to the public in addition to posting the presentation on our website for viewing.
On October 16, 2008, our Geotechnical Engineer Doug Morgan joined other experts from Portland State University and Oregon Department of Geology and Mineral Industries to deliver a customized presentation to the SWHRL Association addressing the issues surrounding the geology of the SW Hills. Due to the recent unfortunate house slide that occurred in this area, the meeting was timely and an informative venue for the many questions the neighbors had about the incident and the security of their homes.
The presentations included discussion of factors that contribute to making the SW Hills susceptible to landslides including steep slopes, weak soils and stormwater. Lessons learned from the numerous landslides triggered by storms in 1996 and 1997 and efforts underway to improve of landslide hazard mapping also were discussed.
Homeowners learned several ways to reduce their landslide risks through inspection and maintenance of their property. The speakers emphasized the importance of keeping stormwater runoff away from slopes and properly maintaining stormwater collection systems. Homeowners were advised to inspect rain gutters, downspouts and area drains for proper operation and to ensure that collected stormwater is not disposed onto steep slopes. Stormwater catch basins and culverts in adjacent streets should also be checked. Periodically checking water lines and irrigation systems for leaks can also help reduce risk.
Homeowners were also presented with information on how to inspect their homes and properties for signs of increased landslide risk, such as growing cracks in walls, foundations, concrete slabs or the ground; out of plumb floors and doors; leaning retaining walls; and decks or patios pulling away from adjacent structures. Concerned homeowners were advised to obtain the services of a geotechnical engineer or engineering geologist for further evaluation of their properties.
The Bureau of Development Services is committed to providing as much information as we can in addition to answering any questions that our citizens. may have. If you have more questions, specific to this topic , contact Site Services Manager Ross Caron at (503) 823-4268.
For more information about scheduling Speakers Program Presentations, contact Outreach Program Coordinator Tiffani Penson at (503) 823-1109.